小麦淀粉与面条质量关系的研究进展

小麦淀粉品质对白盐面条的质量（尤其是煮后的感官特性）有重要影响。直链与支链淀粉的含量及比例是影响面条质量的重要因素,是造成不同小麦品种淀粉糊化和膨胀特性及面条质量差异的物质基础。较低直链淀粉含量的小麦粉具有较好的糊化和膨胀特性,制作的面条煮制时吸水率高,烹调损失低,具有较高的感官评分。优质白盐面条的直链淀粉含量应在22%左右。峰值黏度、稀懈值、峰值时间是影响面条质量的重要糊化参数,这3项参数高的小麦粉适合制作优质面条。高膨胀势或膨胀体积的小麦粉制作的面条中等偏软,光滑且富有弹性,可以作为面条用小麦的重要选择标准。一般认为,直链淀粉含量较低、峰值黏度和稀懈值高、峰值时间长、膨胀势或膨胀体积高的小麦粉适合制作优质白盐面条。其中,直链淀粉含量、峰值黏度和膨胀势是优质面条小麦评价的关键品质性状。     

Comparison of quality of refined and whole wheat tortillas

The use of whole wheat flour instead of refined flour significantly improves the nutritional profile of flour tortillas. However, whole and refined flours differ in properties and in how they process, thus needing process modifications to get the desired product quality. To understand these differences, refined and whole wheat flours, dough and tortillas were evaluated and compared for physical and rheological properties. Overall, whole wheat flour required more water (59% of flour weight) than refined wheat (53%) to make machineable dough. Refined flour doughs were more extensible and softer than whole wheat flour doughs, thus easier to process. Whole wheat flour tortillas were larger, thinner and less opaque than refined flour tortillas. In general, refined wheat tortillas were more shelf-stable than whole wheat tortillas. Smaller particle size and less fiber in the refined wheat flour mainly contributed to the observed differences. Among the whole wheat samples, tortillas from strong flours had excellent shelf-stability, which must be considered when whole wheat tortillas are processed. This will minimize the need to add vital wheat gluten or other dough strengtheners.     

Quality and antioxidant properties of instant noodles enhanced with common buckwheat flour

The objective of this study was to investigate the feasibility of incorporating common buckwheat (Fagopyrum esculentum Moench) into instant noodle formulations. Australian Soft (AS) and Baker's flours were used to evaluate the effects of varying buckwheat contents (0–40%) on noodle quality. The results of texture analysis indicate that noodles made using AS flour produced softer texture whereas there was minimal effect for Baker's flour when buckwheat was incorporated. The colour, measured by L* values, decreased with increased addition of buckwheat for both flours. Fat uptake for noodle samples made from AS flour was only marginally affected, but increased for Baker's flour, when higher levels of buckwheat flour were added. The antioxidant rutin was detected in noodles made from both wheat flours, generally increasing with % buckwheat flour added. These findings indicate that the incorporation of 20% buckwheat into the formulation can be used to enhance the quality of instant noodles.     

Nutritional Evaluation of Wheat–Fenugreek Blends for Product Making

Wheat flour was separately substituted with fenugreek flour (raw, soaked, and germinated) at 5–20% levels for product making. Nutrient analysis of the blends, product development, and their acceptability were carried out. Replacement of wheat flour with fenugreek flour increased the protein, fat, lysine, minerals, and dietary fibre contents proportionately to the level of substitution. Among the composite flours, the blends containing germinated fenugreek flour were found superior in nutritional quality compared to others. However, products, viz., bread, biscuits, noodles, and macaroni prepared from the wheat–fenugreek blends at 10, 15, and 20% levels, were found organoleptically acceptable.     

Physical properties of wheat flour composites dry-coated with microparticulated soybean hulls and rice flour and their use for low-fat doughnut preparation

Air-classified wheat flour was dry-coated with microparticulated rice flour (30%, db) and/or microparticulated soybean hulls (up to 10%, db) using a hybridization system, and the physical properties of the dry-coated wheat flour were examined. The composite wheat flours exhibited the higher water-holding capacity but lower swelling power and oil-holding capacity than their counterpart mixtures. In pasting viscosity, the composites of wheat and rice flours had substantially lower values for peak viscosity and breakdown than did pure wheat flour. The incorporation of soybean hulls to the composites of wheat and rice flours further reduced the peak viscosity. The composites with rice flour and soybean hulls showed slightly higher melting (gelatinization) temperatures but lower melting enthalpy compared to the counterpart mixtures. By using the composite flours for the deep-fat fried doughnut preparation, the oil uptake could be substantially reduced by approximately 30%, in comparison to pure wheat flour or the mixture samples. The composite wheat flours with microparticulated rice flour and soybean hulls produced dough matrices with improved compactness and cell structure, which were attributed to the reduced fat uptake during frying.     

Physical properties of wheat flour composites dry-coated with microparticulated soybean hulls and rice flour and their use for low-fat doughnut preparation

Air-classified wheat flour was dry-coated with microparticulated rice flour (30%, db) and/or microparticulated soybean hulls (up to 10%, db) using a hybridization system, and the physical properties of the dry-coated wheat flour were examined. The composite wheat flours exhibited the higher water-holding capacity but lower swelling power and oil-holding capacity than their counterpart mixtures. In pasting viscosity, the composites of wheat and rice flours had substantially lower values for peak viscosity and breakdown than did pure wheat flour. The incorporation of soybean hulls to the composites of wheat and rice flours further reduced the peak viscosity. The composites with rice flour and soybean hulls showed slightly higher melting (gelatinization) temperatures but lower melting enthalpy compared to the counterpart mixtures. By using the composite flours for the deep-fat fried doughnut preparation, the oil uptake could be substantially reduced by approximately 30%, in comparison to pure wheat flour or the mixture samples. The composite wheat flours with microparticulated rice flour and soybean hulls produced dough matrices with improved compactness and cell structure, which were attributed to the reduced fat uptake during frying.     

Selected nutritional,physical and sensory characteristics of pan and flat breads prepared from composite flours containing fababean

Composite flour blends containing wheat (W), fababean (F), cottonseed and sesame flours were formulated to provide the FAO/WHO/UNU protein requirements for the 2–5 year old child, and evaluated in pan and flat bread applications. Water absorption of composite flour doughs was up to 35% greater than the control but gluten strength and slurry viscosities were markedly reduced. Loaf volume and specific volume of pan breads prepared from composite flours were 25–60% less than that of the control bread but flat breads tolerated the protein supplements extremely well. The W/F flat bread, containing 27% of fababean flour, received acceptable taste, texture and colour scores and was only slightly inferior to the control in puffing and layer separation. Additions of cottonseed or sesame flours to the W/F blend failed to improve sensory properties of the flat breads.     

Processing of commercial peanut cake into food-grade meal and its utilization in preparation of cookies

The commercial cake produced during expeller pressing of peanuts was extracted with n-hexane, and 80% ethanol followed by sieving through 80 mesh, to remove residual oil, pigments, bitter taste and fibrous material. The processed meal exhibited comparable composition with defatted peanut flour prepared in the laboratory by solvent extraction of full-fat peanut meal. However, the processed cake meal exhibited low methionine content and in vitro protein digestibility as compared with defatted peanut flour. The processed cake meal can be blended with wheat flour to the extent of 10% (w/w) to prepare acceptable cookies with improved protein and mineral contents.     

Effects of potato/wheat flours ratio on mixing properties of dough and quality of noodles

The effects of potato flour/wheat flour (PF/WF) ratio on the mixing properties of dough and the quality of noodles were investigated. Substitution of wheat flour with potato flour caused the increases in the water absorption and the protein weakening value (C1-C2) of formulated flours, as well as the decrease in the corresponding dough mixing parameters including dough development time (DDT), dough stable time (DST), initial mixing time (C2), maximum torque during heating (C3), minimum torque of hot paste (C4) and the amount of retrogradation (C5-C4), indicating that the addition of PF weakened dough strength but improved degradation resistance. The textural, cooking, sensory characteristics and microstructure of noodle samples were evaluated. The results indicate that adhesiveness, springiness, broken ratio and cooking lose increased progressively with increasing PF content while the score of sensory evaluation continued to decrease. However, hardness, cooking yield and optimum cooked time for the samples of PF content range from 10% to 20% showed a distinctive variation. Environmental scanning electron microscopy (ESEM) confirmed changes in noodle microstructure as PF addition affected gluten network development. In general, noodles with PF content below 40% were acceptable.     

Nutritional quality of germinated cowpea flour (Vigna unguiculata) and its application in home prepared powdered weaning foods

Amino acid profiles, protein digestibility corrected aminoacid scores (PDCAAS), chemical scores, essential amino acid indexes, andcalculated biological values of control-cowpea flour (CCF), germinated cowpeaflour (GCF) prepared from cowpeas germinated at 25 ^°C for either24 h or 48 h and weaning foods prepared from cowpea flours weredetermined. Locally available rice, cowpea flour, banana-pumpkin slurry,and skim milk powder and sucrose in the ratio 35:35:15:15:5 were used to formulateweaning food containing not less than 15% protein. The ingredients werecooked into a slurry and oven-dried to produce flakes. The nutritional andsensory qualities of the weaning products were evaluated. Germination hadlittle effect on the amino acid profile of cowpeas. In vitro proteinquality and starch digestibility were improved in germinated cowpea flour. The PDCAAS of 24 h germinated cowpea flour (GCF) weaning food washigher (55.49%) than CCF-weaning food (46.74%). Vitamin A activityin 24 h GCF weaning food was higher than in CCF-weaning food. Invitro starch digestibilities of 24 h GCF and 48 h GCF-weaning foods werehigher than that of CCF weaning food. The 24 h GCF-weaning food which hada higher overall acceptability score by sensory panelist than 48 h GCFand CCF-weaning food is recommended for household consumption.     

Effects of semidry flour milling on the quality attributes of rice flour and rice noodles in China

To investigate the effects of semidry-milling on the quality attributes of rice flour and rice noodles, the properties of rice flours and cooking properties of rice noodles prepared with wet-, dry- and semidry-milled rice flours were characterized. The level of starch damage of semidry-milled rice flour at 30% moisture was significantly decreased to the level of wet-milled rice flour (P < 0.05); the whiteness of dry-milled rice flour was decreased compared with wet-milled rice flour (P < 0.05), while that of semidry-milled rice flour was not; the wet- and semidry-milled rice flours showed similar morphology and water hydration properties; the dry milling method reduced significantly the hardness, chewiness, and resilience of rice noodles (P < 0.05) compared with wet-milling, but semidry-milling did not; the cooking qualities of rice noodles produced by semidry-milling were comparable to wet-milling. It indicated the semidry-milling at 30% moisture may provide the protective effects on the characteristics of rice flours, which could be used to produce similar qualities of rice noodles to the wet-milling.     

拉面制作过程和产品感官评价方法的评估

为给拉面质量评价、拉面用粉标准的制定提供感官评价方法,采用走访询问、现场调查和网络交流等方式,收集拉面师傅对实验室制定的拉面制作过程感官评价方法的意见和建议;以餐饮市场常用小麦粉为样品原料,在兰州市和北京市分别开展消费者对拉面产品感官评价要素重视程度的问卷调查,分析、评估和确定了拉面制作过程和产品感官评价方法。88.89%的拉面师傅认为,所制定的拉面制作过程和感官评价方法可以概括拉面制作的整个过程,其对评价指标的重视程度依次为"和面难易程度及面团软硬程度""断条扣数及均匀性""跐面力度及黏手程度""醒发后面团色泽"="拉伸力大小";制定的拉面制作工艺可使大多数小麦粉满足加工工艺要求。消费者对产品感官评价要素的重视程度由高到低为弹性色泽硬度光滑性表观黏性;消费者完全可以区分出拉面用小麦粉的质量优劣。本研究制定的方法可用于拉面制作过程和产品感官质量的评价。在百分制评价体系中,拉面制作过程感官评价赋值分别为"和面难易程度及面团软硬程度"35分、"断条扣数及均匀性"20分、"跐面力度及黏手程度"15分、"醒发后面团色泽"15分、"拉伸力大小"15分;拉面产品消费者感官评价赋值分别为"弹性"30分、"硬度"20分、"色泽"20分、"表观性状"10分、"光滑性"10分、"黏性"5分、"食味"5分。     

Sensory and physicochemical properties of whole wheat salted noodles under different preparations of bran

Whole wheat products have gained popularity in recent years due to the health and nutritional benefits, with Asian salted noodles as one formulation. However, there is a general perception of decreased product quality and sensory acceptance of whole wheat noodles This study examined changes to sensory properties, texture (tensile and compressive strength), color, and cooking loss of noodles prepared from blends of wheat flour and bran that underwent five forms of hydro, thermal, pressure and their combined treatments: autoclaving, extrusion, jet-cooking, puffing, and roasting. Including the control (bran without processing) all six treatments were deemed palatable by sensory panel evaluation despite having statistically significant differences in physiochemical and sensory properties. For instance, 10 of the 22 sensory properties demonstrated significant differences among treatments. Bran processing tended to result in weaker (tensile and compressive strength) and stickier noodles while allowing for greater uptake of water during cooking.     

Investigation of amber durum wheat for production of yellow alkaline noodles

Samples of Canadian amber durum wheat varieties, of various protein content and a composite of export cargo samples, were milled to yield straight-grade and patent flours by reducing semolina and processed into yellow alkaline noodles (YAN). Samples of Canada Hard White Spring (CWHWS) and Canada Western Red Spring (CWRS) were included for comparative purposes. YAN from durum wheat displayed a colour advantage over CWRS and CWHWS YAN. The durum YAN displayed an approximate 9–20 unit greater b* (yellowness) value than CWRS and CWHWS at 2 and 24 h after preparation. This relates to greater yellow pigment and flavonoid contents in the durum flours. All durum wheat YAN exhibited excellent noodle brightness, which was retained over time due to lower levels of the enzymes polyphenol oxidase (PPO) and peroxidase (POD). Durum noodles displayed significantly fewer specks than CWRS and were comparable to CWHWS. Durum wheat YAN cooking quality was equal to or slightly superior to CWRS and CWHWS. Durum wheat flour refinement imparted no significant effects on cooked noodle texture (maximum cutting stress, recovery, resistance to compression). However, the various texture parameters improved with durum wheat protein content and gluten strength.     

Investigation of amber durum wheat for production of yellow alkaline noodles

Samples of Canadian amber durum wheat varieties, of various protein content and a composite of export cargo samples, were milled to yield straight-grade and patent flours by reducing semolina and processed into yellow alkaline noodles (YAN). Samples of Canada Hard White Spring (CWHWS) and Canada Western Red Spring (CWRS) were included for comparative purposes. YAN from durum wheat displayed a colour advantage over CWRS and CWHWS YAN. The durum YAN displayed an approximate 9–20 unit greater b* (yellowness) value than CWRS and CWHWS at 2 and 24 h after preparation. This relates to greater yellow pigment and flavonoid contents in the durum flours. All durum wheat YAN exhibited excellent noodle brightness, which was retained over time due to lower levels of the enzymes polyphenol oxidase (PPO) and peroxidase (POD). Durum noodles displayed significantly fewer specks than CWRS and were comparable to CWHWS. Durum wheat YAN cooking quality was equal to or slightly superior to CWRS and CWHWS. Durum wheat flour refinement imparted no significant effects on cooked noodle texture (maximum cutting stress, recovery, resistance to compression). However, the various texture parameters improved with durum wheat protein content and gluten strength.     

Effects of Flour Particle Size on the Textural Properties of Flour Tortillas

Three wheat flours, hard red winter (HRW), hard white winter (HWW) and soft red winter (SRW), were fractionated by sieving into four different particle size fractions, <38, 38–53, 53–75, and >75 μm. The medium fractions, 38–53 and 53–75 μm, of the HRW and HWW wheat had higher protein contents than the finest and coarsest fractions. The finest fractions had the highest levels of damaged starch. Tortillas made from the medium fractions of HRW and HWW, especially the 53–75 μm fraction, had longer rupture distance and better foldability. The finest fraction yielded tortillas with shorter rupture distance and worse foldability. Fractionation by flour particle size slightly affected protein composition of the flour. Size exclusion-high performance liquid chromatography (SE-HPLC) analyses showed that the compositions of SRW wheat proteins were significantly different from those of HRW and HWW wheat proteins. SRW had more low molecular weight (LMW) and less high molecular weight (HMW) protein than HRW and HWW had. The <38 μm fractions of HRW and HWW had more LMW proteins than other fractions. The amount of LMW proteins of flours correlated negatively with the rupture distance and foldability of tortillas. Particle size of the flours was the major factor affecting the tortilla texture.     

Improved functional properties for soy–wheat doughs due to modification of the size distribution of polymeric proteins

Physical modification of soy flour was shown to greatly improve the dough and baking qualities of soy–wheat (1:1) composite doughs, compared to raw soy flour, giving better stability and R_max, although extensibility was still below that of the wheat dough.Reasons for improvements caused by the physical-modification process were sought by determining the relative size distribution of proteins in the soy–wheat composite doughs by size-exclusion high-performance liquid chromatography (SE-HPLC). Results were expressed as the proportion of ‘unextractable polymeric protein’ (%UPP)—the proportion of the protein that is over 100,000 Da and only extractable after sonication. Protein extracts from the soy–wheat dough were sampled at different stages of dough mixing and fermentation, and their molecular-size distributions evaluated.Unextractable soy proteins were lower in raw soy flour (only 8% UPP) than in two physically-modified soy flours (19 and 34% UPP, respectively). Unextractable polymeric protein was much greater for wheat flour (57% UPP). After mixing a 1:1 soy–wheat composite dough, the %UPP was 36 and 22 (for the two types) when made from physically modified soy flours, compared to 8 for a composite dough using raw soy flour, and 43 for a wheat-only dough. The higher proportion of UPP for the wheat-modified soy doughs was taken as a reason for this composite dough providing better dough and baking qualities. Prolonged fermentation time caused a decrease in UPP percentages for all composite doughs and for the wheat-only dough.     

Proximate composition and selected functional properties of African Breadfruit and sweet potato flour blends

Full-fat African breadfruit flour was used to replace 30, 40, 50, 60 and 70% of sweet potato flour. The chemical composition and functional properties of composite flours showed that they contains more protein, fat, and ash and less carbohydrate than sweet potato flour. With increasing level of supplementation of breadfruit, ash, protein and fat contents increased while carbohydrate decreased. The composite flours possessed higher water absorption than sweet potato flour. The water absorption capacity increased from 20% for sweet potato flour to the range of 85–120% for composite flours. The oil absorption capacities for some composite flours were higher than that for sweet potato but less than that of breadfruit. Composite flours had good foaming capacity but lacked foaming stability. The bulk density of the composite flours was found to be low which will be an advantage in the preparation of weaning food formulations.     

Partial least-squares regression study of the effects of wheat flour composition,protein and starch quality characteristics on oil content of steamed-and-fried instant noodles

Steamed-and-fried instant noodles represent a fast growing product category; however, concern has been raised about high residual oil content by both consumers and manufacturers. To understand how wheat flour characteristics affect the oil content of instant noodles, samples of five Iranian hexaploid landraces, five US/Canadian samples, and seven local commercial wheat flours were analyzed for composition, protein and starch quality, and noodle-making quality. Partial least-squares regression (PLS) analysis between composition, protein quality properties and wheat starch gel properties (independent variables, X) and oil content of instant noodles (dependent variable, Y) resulted in a model that could explain 76.3% of the variability with a cross-validated correlation coefficient of 58.2%. PLS regression coefficient analysis showed that protein content and protein quality were the most important factors, and were negatively correlated with oil content of instant noodles. Starch quality properties, gel hardness, gumminess and chewiness as well as pasting properties were other important contributors. Starch gel hardness, gumminess and chewiness were positively correlated with oil content of instant noodles, while pasting properties were negatively correlated.